An individual authentication device is known which is provided with an imaging unit that captures an image produced by light transmitted through a finger and an image processing unit that processes the image captured by the imaging unit. The image processing unit extracts fingerprint information and vein information from the image, corrects the vein information based on the fingerprint information, and carries out authentication of an individual using the corrected vein information. The image processing unit corrects at least either the rotation angle or the magnification of the vein information based on the fingerprint information.
Also, an image correction device is known in which when a finger is swept on a fingerprint sensor with an inclination, the inclination of a fingerprint image produced by combining partial fingerprint image data obtained by the fingerprint sensor is corrected. The image correction device includes a combination memory, in which the partial fingerprint image data are recorded and stored in sequence to form a fingerprint image, and an image inclination correction mechanism that corrects the inclination of the fingerprint image formed in the combination memory in accordance with the inclination angle at the time of sweeping the finger.
Also, a biometric feature input device is known which includes a one-dimensional or quasi-one-dimensional image sensor, a finger travelling guide, and an image processing mechanism. The finger travelling guide causes a finger to substantially keep a certain distance from an effective pixel section of the image sensor without touching during a relative movement in which a finger and the image sensor are slid with each other. The image processing mechanism generates an image originated from radiation light radiated from the skin surface of the finger caused by diffusion inside the finger by combining one-dimensional or quasi-one-dimensional partial images obtained during the relative movement. Related-art techniques are disclosed in Japanese Laid-open Patent Publication No. 2013-225324, Japanese Laid-open Patent Publication No. 2009-64262, Japanese Laid-open Patent Publication No. 2006-158952, and Japanese Laid-open Patent Publication No. 2005-25414.